27
28
Calculation formula:
C=
Q
U
Where C is measured capacitance, Q is the accumulated charge in the measured
object and U is the voltage of both ends of measured object.
Note: If the withstand voltage of the capacitor is less than the output voltage of
the capacitor, please do not perform measurement to avoid capacitor damage.
When measuring capacitor with polarity, please note that red test lead is the
negative of power output and black is positive, to avoid breaking down the
capacitor with polarity.
9.3.4 Low Resistance Measurement (UT512E)
Note: Be sure the circuit to be measured is de-energized before test. Do not
measure live equipment or circuit.
As a part of insulation testing, the tester has small resistance measurement
function (0.1
Ω
~600
Ω). Without high-voltage output, press capacitance/resistanc
e
button to enter capacitance measurement by default, press again to switch to
resistance measurement mode. “>660
Ω” is displayed, as shown in figure 9.3.4.1.
(With external voltage input, the danger symbol flashes, in such case, do not
press the test butto
n to measure resistance, as shown in figure 9.3.4.2). Under
resistance measurement function, connect the black grounding lead with EARTH
terminal, connect the green shielded lead with GUARD terminal, and disconnect
the red high-voltage lead; connect the green and black alligator clips with the
circuit to be measured; press the test button, then wait for the measurement
result. As shown in figure 9.3.4.3, the continuity of the grounding resistor is
measured.
X. Wire Connection Modes
10.1 . Cable Insulation Resistance Testing
There is leakage current at the surface of inner insulation layer near the end of
cable, the leakage current is included in the measured current of “-” terminal,
causing the measured resistance to be lower than actual insulation resistance.
This mode can be used for non-ultrahigh resistance measurement, as shown in
the figure below:
Fig. 10.1.1 Two-wire connection
Black
Red
Shield
A. Two-wire connection
UT512D/E User Manual
UT512D/E User Manual
Figure 9.3.4.1
Figure 9.3.4.2
Figure 9.3.4.3 Wire connection of low resistance measurement
Do not measure
in live state!
Black
Green
